Conventionally, there are known apparatuses which have a plurality of recording processing paths, and which perform recording by selecting a particular path when recording a video signal onto a storage medium. For example, a recording apparatus described in Japanese Laid-Open Patent Publication No. 7-23339 (data processing apparatus) receives a video signal in a digital stream, and record the signal on a storage medium by selecting an appropriate mode (recording processing path) from among: videorecording mode 1, under which the signal is directly recorded onto a storage medium; videorecording mode 2, under which the digital stream is decoded and thereafter recorded; and videorecording mode 3, under which the digital stream is decoded, and thereafter subjected to an intra-mode compression encoding and recorded.
When recording a video signal onto a storage medium, it is sometimes the case that a remaining duration for which recording is possible is calculated. This calculation is generally performed by dividing the remaining capacity of the storage medium by a recording rate. For example, a recording apparatus described in Japanese Laid-Open Patent Publication No. 11-328937, in the case where a compression encoding is performed with a variable bit rate (i.e., the recording rate varies), ascertains the remaining duration based on a current compression bit rate and remaining capacity, and displays the remaining duration. Japanese Laid-Open Patent Publication No. 11-112897 discloses a technique which detects a data amount or data rate based on program information which is transmitted along with the video/audio data, and judges whether it is possible to perform recording on a storage medium or not.
As a video compression encoding scheme used in a digital broadcast and used in recording onto a DVD, an MPEG encoding scheme is generally used. For example, in a BS digital broadcast, a video signal is transmitted in the form of a well-known MPEG transport stream, and recorded onto a Blu-ray disc (BD) by using a blue-violet laser. Moreover, a video signal is recorded onto a DVD in the form of a well-known MPEG program stream. In such MPEG streams, encoded streams which have been obtained by compression encoding subjecting information such as video and audio to a compression encoding are multiplexed. However, bit rates of the video and audio signals vary depending on the qualities of the video and audio, respectively.
In a conventional recording apparatus, although different recording methods are used depending on the type of input signal and the type of storage medium, the recording apparatus calculates a remaining duration by using a fixed data rate which has previously been determined, regardless of the recording method. Therefore, it has been impossible to determine an accurate remaining duration. For example, in a mode of directly recording a digital stream (stream recording), the data rate may vary, so that it is impossible to accurately calculate a remaining duration with a fixed data rate. Moreover, in a stream recording, the recording apparatus cannot control the data rate of the data stream; therefore, if the data is erased later, it is impossible to guarantee a recording for a duration corresponding to the erased duration. Therefore, there also exists a problem in that an accurate remaining duration cannot be obtained if the remaining duration after an erasure is calculated by the same method.
The present invention has been made in view of the aforementioned problems, and an objective thereof is to determine a recording method based on a type of input signal and a type of storage medium, as well as to determine a remaining amount calculation method which is in accordance with the recording method, and calculate an accurate remaining duration.